KLKB1 and neoplasm: The results showed that the expression of KLKB1 (P < 0.01), IL13RA2 (P < 0.01), ABCC8 (P < 0.01), and PART1 (P < 0.0001) was significantly up-regulated, while PCSK2 (P < 0.01) was significantly down-regulated in PanNET tissues compared to the non-tumor tissues (Figure 7 and Supplementary Material 2).